Rhachis

·noun The Spine.

II. Rhachis ·noun A central cord of the ovary of nematodes.

III. Rhachis ·noun The central cord in the stem of a crinoid.

IV. Rhachis ·noun The median part of the radula of a mollusk.

V. Rhachis ·noun The principal axis in a raceme, spike, panicle, or corymb.

VI. Rhachis ·noun The continued stem or midrib of a pinnately compound leaf, as in a rose leaf or a fern.

VII. Rhachis ·noun The shaft of a feather. The rhachis of the after-shaft, or plumule, is called the hyporhachis.